Disorders of balance and gait lead to immobility, dependence, and a high incidence of debilitating falls in the elderly population. Balance and gait problems are difficult to remedy because so many complex control mechanisms are involved, including sensory and motor systems, musculoskeletal systems, psychological an reflex systems. Studies of control mechanisms underlying posture and gait require a multidisciplinary approach involving expertise in basic sciences (neurophysiology, biomechanics, etc.) as well as in clinical sciences (neurology, neuro- otology, rehabilitation, geriatrics, etc.). The aim of this symposium is to provide the opportunity for basic and clinical scientists from multiple disciplines to interact & discuss new approaches, data, and hypotheses related to posture & gait control mechanisms. By nurturing interdisciplinary, intercontinental interactions, the meeting will identify critical gaps in our understanding of posture & gait and the most promising avenues for future research. This symposium is organized into seven major topics relevant to control mechanisms underlying posture and gait: Aging, Sensorimotor Integration, Vestibular Function, Neurological Disorders, Neural Circuitry, Biomechanical Approaches, and Rehabilitation. Four days of meaningful interaction will be achieved by 1) ten invited oral presentations by international experts on each topic, 2) 40- 50 peer-reviewed short, oral presentations, 3) a special panel discussion on biomechanical vs neurophysiological approaches to control mechanisms underlying posture and gait, 4) up to 100 poster presentations, and 5) published proceedings that will be available at the meeting. Time will be reserved for discussion and fostered by a reception, banquet, and organized social activities. A multidisciplinary, in-depth approach to posture and gait mechanisms is long overdue and warranted for several reasons: 1) The multidisciplinary nature of the problem but the traditional lack of interaction among neurophysiologist, biomechanists and clinicians who study posture and gait: 2) The explosion of new research in the area but absence of a forum for interaction that brings together a critical mass of researchers from the United States and abroad; and 3) The clinical relevance of new information for the diagnosis and rehabilitation of postural/gait disorders. This symposium will focus worldwide energy into identifying the key research questions related to control of posture & gait. The answers to these key questions will open the door to major advances in solving some of the elderly's major problems--falls, immobility, and dependence.